Transcript for Harriet Walter on Her Role as a CIA Operative in 'The Assets'

We'll take a look ahead to the assets. Abc's brand-new miniseries based on the story of how cia officersing traed down a mole if their ranks. A sneak peek at what's coming up. Jane. Wanted two introduce to one of our new officers. Nice to meet you. We missed you around here. Yes, you have. Things have really slipped. Well, I don't know about that. I do know. They have. And we're now going to meet the woman. You look a lot more glamorous. I hope. But she's a fascinating story. She was a woman who began her career in the cia as a typist and became one of its chief mole hunters. She joined the cia because she wanted to travel and that was one of the options when she was in school and people were giving her career choices and she thought, I want to travel and a gap came up in the cia and played it out until she was really -- after retirement she carried on working. And all based on true -- the experience of trying to track down aldridge ames and I love the detail ames was eventually convicted as a spy and she tried to frame your character as the mole. Yes, he was asked by the kgb who are the likely people we can turn and came up with jean and single women, they'll be susceptible to men coming up to them and recruiting them in a bar or hotel and found this all out when he was gee debriefed after he was imprisoned and he said -- then she suddenly realized it wasn't that she was trying to find out who they could recruit. It was that he wanted to pin the blame on her for some of the slippage that had happened on account of him. You have to let me in on a secret. You brits have cornered the market on playing american spies and spy catchers. We're mean and sneaky and you can't tell what we're thinking. We cover up our emotions. No, I don't know. There's a very -- there's something fascinating about spies and they're basically actors, you know, that are putting on a role and have to play out the script till the end once they took on the role and I'm fascinated by the way human beings work. It's a fascinating -- I don't know if it's particularly british. Something that is, we're running out of time. You and dame maggie smith in "downton abbey." My agent said -- she's great. You think I'm being paid to spend a day with maggie smith. Thanks for being on. Harriet waller. "The assets" here on abc at 10:00, 9:00 central.

This transcript has been automatically generated and may not be 100% accurate.

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